Rotary disk drill



Jan. 20, 1931. H. M. PAULSEN 1,789,834

ROTARY DISK DRILL Filed Aug. 8, 1927 7B3 HENBYM PHULSEN Patented Jan.20, 1931 UNITEDSTATES PATENT OFFICE Y HENRY m. PAULSEN, or Los ANqELEs,CALIFORNIA v ROTARY DISK DRILL Application filed August 8,1927. semi No.211,480.

Q My invention relates to rotary disk drills such as are used inthedrilling of 01]. wells,

U being more particularly of the type in which a pair of revoluble disksare mounted in off- 8 set lelation to each other on the opposite sidesof a single drill shank.

In using disk drills of the character referred to, employing commonforms of disks 7 now in use, the dlsks rapidly wear, such wear .10commonly being uneven, so that the periphery of the disk frequentlyassumes an oval (shape due to its lack of rotation-or to intermittentrotation. These faults are undesirteeth are'caused to track duringthe-revolution of the disk asit rotates about the axis of the drillstem, so that the line of contact h etoas hereinafter from the followingdescription and drawings. ,3 1 I Referring to the drawings, which arefor illustrative purposes only, I

Fig. 1 is aside elevation of a drill embodying a form of my'invention.

Fig. 2 is a face view of the drill shown in Fig. 3 is a sectional planview on line 3-.3

ofFig.1.

Fig. 4 is 7 an enlarged sectional view through a portiono f-a disk on.line 4+4 of Fi .2, and

, Fig. is a-sectional view similar to Fig. 4

0 More particularly describing the form of Y teeth, which teeth areprovided with a par-' ticular inclination by means of which the betweeneach tooth and the materialbeing cut isat least approximately inlinewith the axis of. the disk instead of at right angles.

Other objects and advantages will appear less resistance to the rotation'ofthe disk than or body 10 provided at its upper end, with a threadedpin 11 for attachment to the ordinary drill pipe (not shown). The head10 terminates in a downwardly extending sides of the shank having flatfaces 14,.pro-

reduced portion orshank 12, the opposite vided with bosses 15, toreceive the inner faces ofdisks 16. The disks 16-are provided With acentral bore or opening 17 which receives a ring or sleeve 18 and areheld thereon bymeans of a collar 19 held in place by means of afbolt 20,which extends through the collar 19 and sleeve 18 into the shank 12.

The sleeve 18 is 'of slightly greater thickness thanthe disk 16, so thatthe disk may rotate on the sleeve. It is tobe understood that the diskmounting just described may skilled in the art, and that the form of ,bemodified, as will readily-occur to'tho'se mounting adopted may be of anydesired a form, provided the disksare not clamped or held againstrotative movement on their axis. l

Attention is called to the fact that the disks are mounted in offsetrelation to each other, as clearly shown in Figs. 2 and 3, and that thedrill is rotated in thedirection of the arroW'A in Fig. 3, resulting,due to such offset relation, in a rotation of the disks about their axisin the direction of'the arrows B shownin Fig. 2.

Each disk 16has a fiator straight inner 'face25 extendingentirely acrossthe disk to e the base of aseries of teeth 26 forming the cutting edgeof-the disk.

that the rear end 30' of each tooth extends an gularly inwardheyondtheface25 of the disk,

1 as clearly shown in Figs. etand 5, the forward -portion 31 of eachtooth remaining in line with the inner face ofthe disk.

Itis tobe noted'that by bendingthe rear- I V 7 The outer face of thedisk is fiat at its central portion 27, from; which portion it isangularly inclined to- Ward the innerface of the disk, thus diminportionof each tooth inwardly, as above described, the periphery of the disk-isshortened (see Fig. 5) at the rear portion of each tooth.

All of the teeth at the cutting edge of the disk being formed in themanner described, the disk is provided with a variable peripheryconsisting ofv a plurality of teeth,-each tooth having its cutting edgeangularly disposed in two directions, that is angularly .across the edgeof the disk and downwardly toward the axis of rotation of the disk.

The construction of the disks just described aids in the rotation of thedisks and in addition to this rotating cutting action there is also araking or scraping action which is very important as the rear end of thecutting edge of each tooth extends as asharp wedge into the formation.The combined cutting and scraping action just described, due to thenovel shaped teeth on the disks, makes a hole that is slightly roughenedwith spiral projections which materially aids the disks in taking holdand results in the rapid advancement of the hole with comparativelyslight wear of the disks.

the manner in which the teeth are cut, (2) the direction in which theyare set, and (3) the manner in which they are set, which governs theform of the peripery of the outside cutting surface of teeth. It will benoted that in my invention the depth of each tooth is about twenty percent. ofthe disk radius. The direction in which the teeth are set issuch that the rear portion of each tooth extends inward,

thus the cutting edge 31 is bent at an angle which approaches a planecontaining the axis of the disk. The manner of setting the tooth, bykeeping the forward portion'in the original disk contour and bendingtherear portion forward, gives a variable periphery to the tooth surfacefrom which it derives its shearing action, tending to produce grooves inthe hole. This last mentioned feature is also probably instrumental inproducing more rapid rotation of the disks. For instance, assuming thebit 10 to be rotating in the direction of the arrow A, the forward end31 of the tooth 26 (relative to the rotation of the bit) is in contactwith the formation, and as the bit 10 rotates, the disk 16 tends to berotated in the direction of the arrow B, and due to the fact thattheperiphery of the rear end 30 of the teethis lessthan that of the forwardend 3l,the resultant action of the individual teeth in the formation isone of shearing more than scraping, which offers less ressitance to therotation of the disk than would be the case if the entire tooth surface32 had a uniform periphery, as shown by the dotted lines in Fig. 2.Further, since the teeth are set at an angle which approaches a. lineparallel withthe axis of the bit, it is obvious that there will be agreater force tending to rotate the disk than would be the case. if theteeth were set at an angle perpen-' dicular to said axis, in which casethe disk would tend to drag, similar to a plane disk.

It might be added that there is, within certain limits, a definite angleat which the teeth must be set to givethe most eflicient results. Thisangle is dependent upon the size of the disk, being in a ratio'with thediameter of the disk. I find that I obtain very satisfactory results bysetting the teeth in the ratio 'of about one-sixteenthinch for a two andone-half inch disk.

I claim as my invention: 1. For use in combination with the shank memberof a rotary drill bit: a pair of com- I plementary disks rotatablymounted on said shank, the axes of said disks being substantiallyparallel and offset equidistant from the axis of said shank in a planesubstantially perpendicular with said shank axis; said disks havin teethformed in the circumference thereof, said teeth being set with the rearportion'of each tooth, relative to the rotation of the bit, bent fromthe face of the disk toward said shank, the front portion of the toothremaining in the original disk contour. 4

2. For use in combination with the shank member of a rotary drill bit: apair of complementary disks rotatably mounted on said shank, the axes ofsaid disks being substan- V tially parallel and'ofi'setequidistant fromthe axis of said shank in a plane substantially "perpendicular with saidshank'axis; said disks having teeth formed in thecircumference thereof;said teeth having a decreasing periphery toward the axis of said shank.

3. For usein combination .withthe shank member of a" rotary drill bit: apair of complementary disks rotatably mounted'on said shank, the axes ofsaid disks being 'substantially parallehand offset equidistant from theaxis of said shank in a plane substantially perpendicular with saidshank axis;- said disks having teeth formed in the circumferencethereof;said teeth being set in a manner such that the peripheral cutting edgeof each tooth approaches a plane containing the axis of the disk andextends downwardly towards said disk axis, and inwardly'toward the axisofsaid shank. 3 j 4. For use in combination with the shank" member of arotary drill bit :a pair of complementary disks rotatably mountedonfsaid shank, the axes of said disks being substantially. parallel,and'ofl'se't equidistant from the axis of-said shank in a planesubstantially 7? perpendicular with said shank axis; said disks havingteeth formed in the circumference thereof; the rear corners of saidteeth being set toward the axis of said shank in a manner such that theperipheral cutting edge of each tooth approaches a plane containing theaxis of the disk; and a front corner on each tooth remaining in theoriginal disk contour. I m 5. A disk for a rotary drill, adapted to berotatably mounted upon a shank and having teeth formed in thecircumference thereof; said teeth being set so that a correspondingradial face on each tooth remains in the orig-- inal contour of thedisk, the other radial face being bent inwardly from the contour of thedisk toward the axis of the disk. 7

6. A disk for, a rotary drill adapted to be rotatably mounted upon ashank, and having teeth formed in the circumference thereof, said teethbeing formed by serrations having a depth of substantially twentypercent. of the disk radius and set so that a correspondin radial faceon each tooth remains in the original disk contour and a peripheralcutting edge' of each tooth forms an inwardly extending acute angle withthe inside face of the disk.

7. A disk for a rotary drill bit, adapted to be 'rotatably mounted upona shanlgcomprising: a disk member having a serrated periphery and asubstantially flat inner face disposed in a plane parallel with the axisof said shank, said serrations forming circumferential teeth and onecorner of said teeth being set from the plane of said inner face towardthe shank axis.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 28th 40 day of July, 1927. I

HENRY M. PAULSEN.

